Lumped Parameter Liver Simulation to Predict Acute Hemodynamic Alterations Following Partial Resections

Partial liver resections are routinely performed in living donor liver transplantation and to debulk tumors in liver malignancies, but surgical decisions on vessel reconstruction for adequate inflow and outflow are challenging. Pre-operative evaluation is often limited to radiological imaging, which fails to account for post-resection hemodynamic alterations. Substantial evidence suggests post-surgical increase in local volume flow rate enhances shear stress, signaling hepatic regeneration, but excessive shear stress has been postulated to result in small for size syndrome and liver failure. Predicting hemodynamic alterations throughout the liver is particularly challenging due to the dendritic architecture the vasculature, spanning several orders of magnitude in diameter. Therefore, we developed a mathematical lumped parameter model with realistic heterogeneities capturing inflow/outflow of the human liver to simulate acute perfusion alterations following surgical resection. Our model is parameterized using clinical measurements, relies on a single free parameter, and accurately captures established perfusion characteristics. We quantify acute changes in volume flow rate, flow speed, and wall shear stress following variable, realistic liver resections and make comparisons to the intact liver. Our numerical model runs in minutes and can be adapted to patient-specific anatomy, providing a novel computational tool aimed at assisting pre- and intra-operative surgical decisions for liver resections.